Locomotion and Movement Question 34
34. The functional unit of contractile system in striated muscle is
(a) myofibril
(b) sarcomere
(c) Z-band
(d) cross bridges
Show Answer
Answer : b
Hints & Solutions
(b) A skeletal muscle consists of a bundle of long fibres running the length of the muscle. Each fibre is a single cell with many nuclei. Skeletal muscle is also called striated muscle because the regular arrangement of the myofilaments creates repeating pattern of light and dark bands. Each repeating unit is a sarcomere, the basic functional unit of the muscle. The borders of the sarcomere are the $Z$ lines, which line up in adjacent myofibrils and contribute to striations visible with a light microscope.
